JP7394252B1 - Protruding type wind duct structure perpendicular to the vertical direction and construction method at deep subway station - Google Patents

Abstract

[Problem] To provide a protruding type wind duct structure perpendicular to the vertical direction and a construction method in a deep subway station. [Solution] Construction is carried out using a method that combines open-cut excavation and undercut excavation. A wind duct and an outside air intake duct extend from the first floor underground and lead to the left and right piston ventilation shafts, the exhaust shaft, the outside air introduction ventilation shaft, and the evacuation entrance, respectively. The 2nd to 5th basement level is the open cut part of the second stage. The fourth underground level is connected to the station hall level of the station main body, and the fifth underground level is connected to the section tunnel and the platform level of the station main body. During train operation, the piston wind and heat generated by entering and exiting the station from the five underground levels of the windway pass through the main body of the windway, connect to four horizontal windways, and then propagate to the outside environment via four ventilation shafts. do. [Effect] Construction can be performed more easily, accelerating the construction progress and shortening the construction period. [Selection diagram] Figure 1

Description

The present invention relates to the technical field of design and construction of urban rail transportation, and more particularly to a projecting type wind duct structure orthogonal to the vertical direction in a deep subway station and a construction method.

As an important component of urban transportation, subways play an increasingly beneficial role for passenger transport traffic in densely populated cities. Subway undercut excavation stations are generally installed under urban roads with relatively large flow rates, and the station body generally has an arched tunnel structure, and its auxiliary structure extends horizontally from the main structure and sinks into the ground. The part exposed from the ground is generally installed outside the road red line. Airways are a typical auxiliary structure that is generally installed at both ends of a station, adjacent to the section tunnel, and communicated with the ground through ventilation shafts, connecting the sealed underground station to the outside environment and exchanging internal and external air. This will ensure that the air inside the station is fresh and comfortable. In general, in order to improve ventilation efficiency and realize the purpose of energy saving and emission reduction, the shorter the air path, the better, while ensuring that there is space for the blower to operate normally. In accordance with the requirements of the latest code <<Standard for Ventilation Air Conditioning and Heating Design in Urban Rail Transit>>, the length of the piston air channel should not exceed 40 m when fully enclosed platform doors are used.

If it is possible to install a wind pavilion exposed from the ground directly above a subway station that requires deep undercut excavation, the design of an extended wind passage would eliminate its advantages and express its shortcomings. The extended type design makes the wind channel long, which is disadvantageous for the exchange of inside and outside air, while the shaft of the wind channel is relatively small, and there are relatively many side passage changes during construction, which is high risk and slow slag discharge. , construction efficiency is relatively low.

To this end, in view of the above deficiencies, the designers of the present invention have devoted themselves to research and design, and have compiled the experience and results of engaging in related industries for many years to create a design that is perpendicular to the vertical direction in a deep subway station. We researched and designed the protruding wind duct structure and construction method to overcome the above deficiencies, make better use of the vertical space above the deep station, improve ventilation efficiency, reduce the amount of construction work, and make it greener. Realize the philosophy of environmentally friendly energy saving and emission reduction.

An object of the present invention is to provide a protruding type wind duct structure orthogonal to the vertical direction in a deep subway station and a construction method, which can effectively shorten the length of the wind duct and utilize the space above the deep subway station. In addition, the undercut excavation can be carried out in conjunction with the main structure of the station and the section tunnel, improving efficiency and shortening the construction period. The construction method is a combination of open cut excavation and undercut excavation, and an appropriate method is used depending on the local circumstances to effectively balance construction costs and construction site, and maximize production. It can be realized.

In order to achieve the above object, the present invention discloses a protruding type wind duct structure perpendicular to the longitudinal direction in a deep subway station, comprising a wind duct separation part and a wind duct main part,
The air duct separation part is located on both sides of the air duct main part, and the air duct separation part and the air duct main part are performed at the same time during construction, and the air duct separation part includes a left line piston ventilation shaft, a right line piston ventilation shaft, It is equipped with an exhaust shaft, an outside air introduction ventilation shaft, and a part of the horizontal passageway of the windway, and the said part of the horizontal passageway of the windway includes a part of the horizontal piston windway passage of the left piston, a part of the horizontal passageway of the right piston windway, It is equipped with a part of the ventilation duct horizontal passage and a part of the outside air intake passage. , the third stage open-cut foundation shaft and the remaining wind passageway are divided into the remaining left piston wind passageway, the remaining right piston wind passageway, and the remaining right piston wind passageway. It is provided with an exhaust air passageway and the remaining outside air intake air passageway, and the part of the left line piston airway side passageway and the remaining left line piston airway side passageway communicate with each other to form a left line piston airway side passageway. , the part of the right line piston air passage horizontal passage and the remaining right line piston air passage horizontal passage communicate with each other to form a right line piston air passage horizontal passage, and the part of the right line piston air passage horizontal passage and the remaining ventilation passageways communicate with each other to form a ventilation passageway, and the part of the outside air introduction passageway and the remaining outside air introduction passageway communicate with each other to form an outside air introduction passageway. The windway main part is located between the section tunnel and the station main part, forming a side passage.

Further discloses a construction method of a protruding type wind duct perpendicular to the longitudinal direction in a deep subway station comprising a wind duct separation part and a wind duct main part,
The construction of the wind duct separation part is as follows:
Step 1: Construct a closed ring beam at the positions exposed from the ground of the left line piston ventilation shaft, right line piston ventilation shaft, exhaust shaft, and outside air introduction ventilation shaft, and install the foundation embedded members to raise the shaft turret. .1 and
step 1.2 of excavating the earth and rock of the shaft and supporting it as it is excavated;
step 1.3 of initially spraying concrete and installing lattice steel frames and reinforcing bar mesh;
step 1.4 of applying shotcrete to seal the surrounding rock;
step 1.5, repeating steps 1.2 to 1.4 until drilling to the bottom elevation of the shaft;
step 1.6 of sealing the bottom of the shaft;
Three lattice steel frames were connected and erected at the positions of the left piston ventilation shaft, right piston ventilation shaft, exhaust shaft, and outside air introduction ventilation shaft, respectively, and mortar anchor bolts were driven. Step 1.7 of setting
Some left piston wind passages are excavated in the entire cross section of the left piston ventilation shaft, right piston ventilation shaft, exhaust shaft, outside air introduction ventilation shaft, some right piston ventilation passages, and one right piston ventilation shaft. step 1.8, installing anchor bolts from the side passages of the ventilation ducts in the section and the lateral passages of the part of the outside air intake ducts, tying up the reinforcing bars, and spraying concrete;
Step 1.9 of laying the bedrock waterproofing layer and constructing the bedrock;
step 1.10 of laying the remaining waterproof layer and performing secondary lining of the arch and side walls;
repeating steps 1.8 to 1.10 until some piston airway cross passages are completed, step 1.11;
The construction of the main body of the wind duct is as follows:
Before excavation, the water level in the pit should be lowered, the groundwater level should be lowered to a point 1 m lower than the final excavation surface of the foundation pit, and a water intake channel should be built on the shoulder of the slope and soil hardening should be carried out. Step 2.1 of preventing surface water from seeping into the slope;
Step 2.2 of driving one stage of steel pipe piles into the rocky strata;
Step 2.3 of constructing the top beam, erecting the flange brace, and driving prestressed anchor bolts;
The earth and sand are excavated downward, and the first stage open-cut foundation shaft is excavated one layer at a time from top to bottom. After excavation, one layer of concrete is sprayed to seal the surrounding rock, and then anchor bolts are driven. step 2.4 of installing the shotcrete panels after installing the reinforcing steel mesh;
step 2.5, in which the first stage open-cut foundation shaft is excavated one layer at a time up to the elevation of the dome leg foundation, that is, the elevation of the top of the primary lining of the horizontal lateral passage, and the construction of the undercut excavation dome portion begins;
step 2.6 of pouring a previously placed pipe roof in the open cut foundation pit;
step 2.7 of sealing the face with 100-200 mm thick shotcrete or 200-500 mm thick concrete;
Step 2: First, tunnels on both sides are excavated in sequence, concrete is sprayed to seal the surrounding rocks, lattice formwork is erected, temporary steel shoring is erected, reinforcing bars are tied together, and concrete is sprayed. .8 and
Step 2: After each lattice formwork is erected, dig out the soft soil of the lattice legs and install a 100mm thick shotcrete underlayment as a foundation for the lattice legs to ensure the lattice is stable. .9 and
Two central guide shafts were excavated about 5 meters apart in the vertical direction, and after the excavation, concrete was immediately sprayed to seal the surrounding rocks, lattice formwork was erected, temporary steel shoring was erected, and a reinforcing bar net was installed. Step 2.10 of tying and spraying concrete;
step 2.11 of constructing the dome structure and removing the central temporary shoring in stages;
step 2.12 of excavating the second stage foundation shaft while being protected by the dome structure;
step 2.13 of excavating to the bottom elevation of the windway cross passage, then temporarily stopping the excavation, opening horsehead gates on both sides and starting to enter the tunnel, and excavating the four remaining windway cross passages;
After completing the secondary lining construction for the remaining windway side passages, we continued to excavate the lower part of the earth and sand, and built the third stage foundation from the bottom elevation of the windway sideways along the outer contour of the station main structure. step 2.14 in which the excavated portion of the well is partitioned vertically;
Step 2.15 of continuing to excavate downward into the steel pipe pile and immediately shoring;
When a pit is excavated more than 300mm from the base of the foundation, the foundation is inspected, the remaining soil is manually dug out, and after the excavation reaches the design elevation, the foundation is leveled immediately to drain the water that has accumulated inside the pit. step 2.16, in which the underlayment should be applied immediately;
step 2.17 of carrying out undercut excavation construction of the station body from the foundation shaft of the windway body;
After undercutting the entire station structure and entering the tunnel, we will lay a waterproof layer for the windway main structure, and then begin constructing the secondary lining structure for the windway main body from bottom to top. Step 2.18 and
After the secondary lining structure of the wind channel main body concrete reaches 75% of the design strength, it is characterized by including step 2.19 of backfilling with earth and sand, compacting it, and restoring the ground to its original state.

In step 2.6, in order to ensure the construction accuracy of the long pipe roof, the guide steel pipe with a diameter of 140 mm and a wall thickness of 5 mm is set to L=0.8 m, and the long pipe roof covers the horizontal depth of the entire dome.

The long pipe roof is 16 m long, and each section is made up of 4 m long hot-rolled seamless steel pipes connected with screws.Cement slurry is used for injection, with a water-cement ratio of 1:1 and injection pressure. After the injection is completed, the steel pipe is filled with M7.5 cement mortar to strengthen the strength of the pipe roof.

The second stage open cut foundation shaft in step 2.12 is divided into two parts, one part continues to excavate downward from the first stage foundation shaft, and the other part continues to excavate from the undercut excavation part to the dome. Top-down excavation is carried out downward while being protected by the ground.During construction, the principle of first-branch-back excavation is used, and after excavation, one layer of concrete is immediately sprayed to seal the surrounding rock, and then anchor bolts are driven. , install the shotcrete panels after installing the reinforcing steel mesh.

In step 2.13, the tunnel entrances of the remaining left piston wind passages and the remaining outside air introduction wind passages are located below the first stage open cut foundation shaft, and the remaining right piston wind passages are located below the first stage open cut foundation shaft. The tunnel entrances of the road side passage and the remaining ventilation road side passage are located below the dome.

Entry into the tunnel of the remaining left piston wind passage below the open cut foundation shaft and the remaining outside air introduction wind passage is performed by full-section excavation, specifically,
Step A: excavating the entire cross section, installing anchor bolts, tying up the reinforcing steel mesh, and spraying concrete;
Step B of laying a bedrock waterproof layer and constructing the bedrock;
Step C, in which the remaining waterproof layer is laid and secondary lining is applied to the arch part and side walls, and the secondary lining progress of the arch part and side walls is one excavation progress slower than that of the inverted rock arch; including.

The remaining right-hand piston wind passageway and the remaining ventilation passageway below the dome are excavated by the middle wall construction method, and specifically,
The left-hand shaft was excavated, concrete was immediately sprayed initially to seal the surrounding rocks, lattice steel formwork and vertical temporary I-shaped steel supports were erected, and the reinforcing bar network was tied together, then concrete was poured to a thickness of 150 mm. Step A of spraying
A right-hand shaft was excavated with a shift of 0.5 m, concrete was immediately sprayed initially to seal the surrounding rock, lattice steel forms were erected, and each lattice was erected to ensure that the lattice was stable. Step B, in which the soft soil at the base of the lattice legs should be excavated and a 100mm thick shotcrete underlayment should be laid as a foundation for the lattice legs;
After the dome reaches its design strength, step C of removing the temporary steel beam support and constructing a secondary lining structure for the wind channel at the horse gate;
The length of the horse head part is about 3 m, the excavation depth is set to 0.5 m or less, and step D is excavated using the full cross-section method after leaving the horse head part.

The four remaining air passages and the part of the air passage excavated from the ventilation shaft in step 1.11 are joined together to form a completely communicating air passage.

In step 2.17, the station main body, which is undercut excavated from the foundation shaft of the windway main body, is excavated using the three-step construction method and the seven-step method.

As can be seen from the above content, the longitudinally orthogonal protruding wind duct structure and construction method in a deep subway station according to the present invention has the following effects.

First, the vertical space above the deep station will be effectively used to improve the utilization rate of underground space, make the station structure more concentrated, and reduce the impact on the surrounding architectural environment.

Second, it is possible to effectively shorten the length of the wind duct at the deep station, improve ventilation efficiency, and save energy and reduce emissions.

Thirdly, in the construction stage, the foundation shaft of the wind passage main body may be used as the construction shaft of the station main body and the section tunnel, and the construction can be carried out in cooperation with the station main body and the section tunnel, thereby shortening the construction period.

Fourth, the construction scheme that combines open-cut excavation and undercut excavation reduces the construction site, provides multiple working surfaces, greatly improves construction efficiency, and effectively saves costs and manpower and material resources. can do.

The detailed contents of the present invention will become clear from the following description and drawings.

FIG. 1 is a general plan view showing a protruding type air duct perpendicular to the vertical direction of a protruding type air duct structure perpendicular to the vertical direction in a deep subway station according to the present invention. FIG. 2 is a sectional view taken along the line AA in FIG. FIG. 3 is a sectional view taken along the line BB in FIG. FIG. 4 is a cross-sectional view along the C-CA-A direction in FIG. 1. FIG. 5 is a cross-sectional view taken along the DDA-A direction in FIG. FIG. 6A is a construction plan diagram of the present invention. FIG. 6B is a construction plan diagram of the present invention. FIG. 7A is a schematic diagram of the construction of the wind duct main body according to the present invention. FIG. 7B is a schematic diagram of the construction of the wind duct main body according to the present invention. FIG. 7C is a schematic diagram of the construction of the wind duct main body according to the present invention. FIG. 7D is a schematic diagram of the construction of the wind duct main body according to the present invention. FIG. 7E is a schematic diagram of the construction of the wind duct main body according to the present invention. FIG. 7F is a schematic construction diagram of the wind duct main body according to the present invention. FIG. 7G is a schematic construction diagram of the wind duct main body according to the present invention. FIG. 7H is a schematic diagram of the construction of the wind duct main body according to the present invention. FIG. 8 is a schematic diagram of construction of a station main body into a tunnel according to the present invention. FIG. 9 is a schematic diagram of excavation of a shaft according to the present invention.

1 to 5 show a protruding type wind duct structure perpendicular to the longitudinal direction in a deep subway station according to the present invention.

The vertically orthogonal protruding wind duct structure and construction method in the deep subway station include the following.

As shown in FIGS. 1 to 5, the projecting type wind duct structure applied to a subway station where deep undercut excavation is performed according to the present invention includes a wind duct separation part 1 and a wind duct body part 2, The parts 1 are located on both sides of the air duct body part 2, and the air duct separation part 1 and the air duct main part 2 can be performed at the same time during construction, thereby shortening the construction period. The air passage separation part 1 includes a left-line piston ventilation hole 11, a right-line piston ventilation hole 12, an exhaust hole 13, an outside air introduction ventilation hole 14, and a part of the air passage. is equipped with a part of the left piston air passage 15, a part of the right piston air passage 16, a part of the exhaust air passage 17, and a part of the outside air introduction air passage 18. The road body part 2 is divided into four parts depending on the construction process, namely, the first stage open cut foundation shaft 21, the undercut excavation dome part 22, the second stage open cut foundation shaft 23, the third stage open cut foundation shaft 24, and The remaining horizontal wind passages may be divided into the remaining horizontal piston air passages 25, the remaining piston air passages 25 on the left, the horizontal piston air passages 26 on the right, and the horizontal horizontal exhaust air passages. 27 and the remaining outside air introduction wind passage 28, the part of the left line piston air passage 15 and the remaining left line piston air passage 25 communicate with each other to form the left line piston air passage lateral passage. The part of the right line piston air passage lateral passage 16 and the remaining right line piston air passage lateral passage 26 communicate with each other to form a right line piston air passage lateral passage, and the part of the right line piston air passage lateral passage The passage 17 and the remaining cross-exhaust passage 27 communicate with each other to form a cross-exhaust passage, and the part of the external air introduction passage 18 and the remaining cross-exhaust air passage 28 communicate with each other. The wind passage main part 2 is located between the left and right line section tunnels 31 and 32 and the station main part 33, and after the wind passage is put into use, The piston wind entering the station (section tunnel) from the section tunnel (station) enters the piston airway side passage from the airway body, and then communicates with the outside environment through the piston ventilation shaft.

The station main part 33 communicates with the open-cut foundation shaft 24 of the third stage, and the communication method is shown in FIGS. 2, 3, and 5. It communicates with the well 24, and the communication method is shown in FIGS. 2, 3, and 4. After the station is put into use, the train enters the windway main body 2 through the right track tunnel 32 and then enters the station main body 33 to realize the station, and the train enters the station main body 33. The train enters the windway main body 2 through the train, enters the right line section tunnel 32, and exits the station. The piston wind due to the high-speed movement of the train enters the air passage main body 2 while being caught up in the train, and then passes through the left line and right line piston air passages 25, 15 and 26, 16 to the left line and right line piston ventilation holes 11 and 12. and thereby balance the wind pressures of the external environment and the internal environment of the subway track running area. The turbid gas inside the station main body enters the ventilation ducts 27, 17 through the ventilation pipes between the station main body 33 and the ventilation pipe main body 2, passes through the ventilation shaft 13, and is then discharged to the outside environment, and is discharged to the outside environment. The air enters the outside air intake ducts 18 and 28 through the outside air introduction ventilation shaft 14, then enters the air duct main body 2, and finally enters the station main body 33, thereby separating the non-track running area of the station and the external environment. It will realize gas exchange and ensure that the air inside the station is fresh.

The present invention further discloses a method for constructing a protruding windway perpendicular to the longitudinal direction in the deep subway station, including the following steps:

Referring to FIGS. 4 to 6A and 6B, the construction of the airway separation part 1 includes the following steps 1.1 to 1.11.

Step 1.1 Install closed ring beams at the positions exposed from the ground of the left line piston ventilation shaft 11, right line piston ventilation shaft 12, exhaust shaft 13, and outside air introduction ventilation shaft 14, and pull up the shaft turret. Foundation embedded components can be attached.

Step 1.2 Excavate the earth and rock for the shaft and support it as it is excavated. The shaft is excavated in layers from top to bottom, and the excavation compass is set to the spacing of the steel grid. In this example, a hollow injection anchor bolt with a joint growth area of ψ25 is used, the driving length L is 2.5 m, the driving angle is 15°, and the left piston ventilation hole 11 and the right piston ventilation hole 12 are Two shafts, the exhaust shaft 13 and the outside air introduction ventilation shaft 14, may be excavated simultaneously as one shaft.

Step 1.3 Initial spraying of concrete and installation of grid steel and reinforcing bar mesh. Clearances should be inspected before installation to prevent under-excavation. Preferably, shotcrete with reinforced mesh of ψ6200 mm x 200 mm may be used in locations where the surrounding rock conditions are better in this example, and no grid steel frame is attached.

Step 1.4 Apply shotcrete to seal the surrounding rock. When spraying concrete, care should be taken to control the wind pressure to (0.1 to 0.2 MPa) to avoid excessive rebound of the sprayed concrete due to too high wind pressure. The nozzle should be perpendicular to the surface to be sprayed, the distance should be less than 1.5 m, and the concrete should be sprayed sequentially from bottom to top in areas.

Step 1.5 Repeat steps 1.2-1.4 until drilling to the bottom elevation of the shaft.

Step 1.6 Seal the bottom of the shaft.

Step 1.7 Connect and erect three lattice steel frames at the positions of the respective wind passages from the left piston ventilation shaft 11, right piston ventilation shaft 12, exhaust shaft 13, and outside air introduction ventilation shaft 14, respectively. Then, a mortar anchor bolt with a diameter of Φ28 was installed, with a length of 4 m and an angle of 15°.

Step 1.8 Excavate a portion of the left piston air passage horizontal passage 15 and a portion of the left piston ventilation hole 11, right piston ventilation hole 12, exhaust ventilation hole 13, and outside air introduction ventilation hole 14, respectively. Anchor bolts are installed from the right-line piston air passage 16, some of the exhaust air passages 17, and some of the outside air introduction air passages 18, the reinforcing steel nets are tied together, and concrete is sprayed.

Step 1.9 Lay the bedrock waterproofing layer and construct the bedrock.

Step 1.10 Lay the remaining waterproofing layer and apply the secondary lining of the arch and side walls. The progress of the secondary lining of the arch portion and side walls is one excavation progress slower than that of the inverted arch made of rock.

Step 1.11 Some of the left piston air passages 15, some of the right piston air passages 16, some of the exhaust air passages 17, and some of the outside air introduction air passages 18 are all Repeat steps 1.8 to 1.10 until completed and merge with the side passage of the main body part 2 of the wind channel.

Referring to FIG. 5, FIGS. 7A to 7H, and FIG. 8, the construction of the wind channel main body portion 2 includes the following steps 2.1 to 2.19.

Step 2.1 Referring to FIG. 7A, in one embodiment, because the elevation difference in the terrain is relatively large, the top of the foundation pit can be sloped and earth nail wall shoring is used. Before excavation, the water level in the pit should be lowered, the groundwater level should be lowered to a point 1 m lower than the final excavation surface of the foundation pit, and a water intake channel should be built on the shoulder of the slope and soil hardening should be carried out. Prevent surface water from seeping into the foot of the slope.

Step 2.2 Driving one stage of steel pipe piles into the rock strata. In this example, the depth of the foundation pit is deeper and no steel pipe piles are driven, so the excavation of the earth and rock is controlled by smooth plasting. Then, manually excavate the area 3 meters away from the designed wall. It is necessary to measure multiple times during construction to prevent over-excavation or under-excavation.

Step 2.3 Construct the top beam, erect the flange brace, and drive the prestressed anchor bolts.

Step 2.4 Excavate the earth downwards and shoring immediately. The open-cut foundation shaft 21 of the first stage will be excavated one layer at a time from top to bottom, and the excavation compass will be set at the spacing of the anchor bolts, and excessive excavation will be prohibited. After excavation, a layer of concrete is immediately sprayed to seal the surrounding rock, then anchor bolts are driven, reinforcing bars are placed, and shotcrete panels are constructed.

Step 2.5 The first stage open cut foundation shaft 21 is excavated one layer at a time up to the elevation of the dome leg base, that is, the top elevation of the primary lining of the horizontal passageway, and the construction of the first stage open cut foundation shaft 21 is completed. After a temporary stop, construction of the undercut excavation dome portion 22 begins.

Step 2.6 Pour the previously placed pipe roof into the open cut foundation pit. In order to ensure the construction accuracy of a long pipe roof, a guide steel pipe with a diameter of 140 mm and a wall thickness of 5 mm may have a length of L=0.8 m. The long pipe roof should cover the entire horizontal depth of the dome, and the length of the dome in this example is 14.5 m, so the selected 16 m long pipe roof has a length of 4 m per section. It is made by connecting hot-rolled seamless steel pipes (diameter 108 mm, tube wall thickness 6 mm) with screws. Cement slurry is used for injection, with a water-cement ratio of 1:1 and an injection pressure of 0.5 to 2.0 MPa. After the injection is completed, the steel pipe is filled with M7.5 cement mortar to strengthen the pipe roof.

Step 2.7 Seal the face with 100-200 mm thick shotcrete or 200-500 mm thick concrete depending on the surrounding rock conditions to prevent instability of the face.

Step 2.8 As shown in Figure 7B, the span of the face is relatively large and the receiving force situation at the boundary between the open cut foundation shaft and the undercut excavation part is complicated, so the undercut excavation dome part is partially Suitable for use in tunnel excavations. First, we excavated shafts I and J on both sides one after another, immediately sprayed C25 concrete to seal the surrounding rocks, erected lattice formwork, erected temporary steel shoring, and tied up the reinforcing bar network. You can also spray concrete.

Step 2.9 After each lattice formwork is erected, the soft soil of the lattice legs should be dug out and a 100mm thick shotcrete underlayment should be laid as the foundation of the lattice legs, so that the lattice is Ensure stability. If necessary, a solid wood board underlay may be installed.

Step 2.10 Two center shafts K and L are excavated to the left and right with a vertical shift of approximately 5 m. After excavation, C25 concrete is immediately sprayed to seal the surrounding rocks, lattice formwork is erected, and temporary steel The shoring is erected, the reinforcing bars are tied together, and concrete is sprayed.

Step 2.11 As shown in Figure 7C, the dome structure should be installed and the central temporary shoring removed in stages, monitoring measurements should be strengthened during the removal of the shoring, and based on the monitoring measurement results. Provide feedback and guidance on construction, immediately adjust the length of the part from which the shoring has been removed, and ensure the safety of the arch. Large arches should be preformed and not partially poured.

Step 2.12 As shown in FIG. 7D, the second stage foundation pit 23 is excavated while being protected by the dome structure. The second stage open cut foundation shaft is divided into two parts, one part continues to excavate downward from the first stage foundation shaft, and the other part continues to excavate downward from the undercut excavation part while being protected by a dome. top-down drilling is performed. During construction, the principle of digging first and digging is still used, and after excavation, a layer of concrete is immediately sprayed to seal the surrounding rock, then anchor bolts are placed, and the reinforcement mesh is hung before the shotcrete panels are installed. However, excavation cannot continue unless the support strength meets the design requirements.

Step 2.13 As shown in Figure 7E, excavate to the bottom elevation of the windway cross passage, then pause the excavation, open the horsehead gates on both sides and begin to enter the tunnel, and then complete the four remaining windway cross passages. excavate.

Said step 2.13 may include the following key points.

First, in the four remaining wind passages, the tunnel entrances of the remaining left piston wind passages 25 and the remaining outside air introduction wind passages 28 are in the first stage. including that the tunnel entrances of the remaining right-hand piston wind channel lateral passage 26 and the remaining ventilation duct lateral passage 27 are located below the dome, which is connected to the dome structure. This is to ensure construction safety by reducing disturbances to the tunnels, and as a result, the two types of cross passages use different excavation methods.

Second, the remaining left line piston wind passageway 25 and the remaining outside air introduction wind passageway 28 below the open cut foundation tunnel are entered into the tunnel by full cross-sectional excavation, and specifically, the following steps A to Contains C.

Step A: Excavate the entire section, install anchor bolts, tie up the reinforcing steel mesh, and spray concrete.

Step B: Lay the bedrock waterproofing layer and construct the bedrock.

Step C: Lay the remaining waterproof layer and perform secondary lining for the arch and side walls. The progress of the secondary lining of the arch portion and side walls is one excavation progress slower than that of the inverted arch made of rock.

Thirdly, the remaining right-line piston wind passageway 26 and the remaining ventilation passageway 27 below the dome are excavated by the middle wall construction method (CD method), and specifically, the following steps A to D are carried out. include.

Step A: Excavate the left-hand shaft, immediately spray the initial concrete to seal the surrounding rock, erect the 25-grid steel formwork and the vertical temporary I22 type steel shoring, and tie the reinforcing bar network to a 150mm thickness. spray concrete.

Step B: Excavate the right-hand shaft with a 0.5 m offset, immediately spray the initial concrete to seal the surrounding rock, erect the lattice steel formwork, and erect each lattice to ensure that the lattice is stable. After installation, the soft soil at the base of the lattice legs should be dug out and a 100mm thick shotcrete underlayment should be laid as a foundation for the lattice legs.

Step C: After the dome reaches its design strength, the temporary steel support 22 is removed and a secondary lining structure for the wind channel at the horse gate is constructed.

Step D: The length of the horse head part is about 3 m, the excavation depth is set to 0.5 m or less, and excavation is carried out using the full cross-section method after leaving the horse head part, and the steps are shown in 2 above.

Fourth, the remaining four horizontal wind passages finally merge with some of the horizontal passages excavated from the ventilation shaft in step 1.11, respectively, to form completely communicating horizontal passages. . When both construction faces approach, one should stop construction and the other should continue digging.

Step 2.14 After completing the secondary lining of the remaining wind passageways, continue excavating the lower soil. The excavated portion of the third stage foundation pit 24 is vertically partitioned from the elevation of the bottom of the wind passageway along the outer contour line of the station main structure. The bottom of the second phase foundation shaft, which has no vertical overlap with the station outline, will be sealed with 200mm thick C20 concrete.

Step 2.15 Continue to excavate downward into the steel pipe pile and immediately shoring as shown in Figure 7F. The excavation of the foundation pit should be carried out hierarchically and sequentially from top to bottom, the excavation height should be strictly controlled, the construction length of each part should be the longitudinal spacing of the rib beam, and after excavating to the design elevation. Immediately cover the net, spray concrete, cast prestressed anchor cables, and install rib beams or rib columns to shorten the exposure time of unsupported foundation shafts and improve the height of the rock layer in the same horizontal construction section. Construction should be carried out from low points to low points. Excessive excavation of the subsoil is prohibited before the shoring is suitable for normal use.

Step 2.16 Once the pit has been excavated to a depth of 300 mm or more from the base of the foundation shaft, the foundation shaft will be inspected, the remaining soil will be manually dug out, and after excavation to the design elevation, the foundation shaft will be leveled immediately to ensure that no dirt accumulates inside the shaft. Water should be drained and underlayment applied immediately.

Step 2.17 By using the foundation shaft of the wind passage main body as the construction shaft of the station main body and section tunnel, slag transportation and slag discharge efficiency can be improved, and in the case of section tunnels excavated using shield excavation. can facilitate the lifting of the shield excavator by means of the foundation shaft of the main body of the wind duct. In order to realize the above function, referring to FIG. 8, the station body should use the following steps 1 to 7 to excavate an undercut from the foundation hole of the wind channel body.

Step 1: Determine the grade of surrounding rock and decide on the shoring scheme and undercut excavation method. In this example, since the rock around the station main body entering the tunnel is grade II, no advance support measures were installed, and the excavation was carried out using a three-step construction method and a seven-step method, as shown in FIG. 8.

Step 2: Excavate the upper arc-shaped shaft a, immediately after excavation, initially spray concrete to seal the surrounding rocks, drive anchor bolts and erect the lattice steel frame, spray concrete again, and then spray the upper arc-shaped shaft a. Complete the primary lining in a.

Step 3: Excavate the stairs B and C on both sides of the center and install the primary lining for these sections.

Step 4 Excavate the stairs d and e on both sides of the lower part and install the primary lining. The stairs of the upper arc-shaped shaft, the central double-side shaft, and the lower double-side shaft are sequentially located 2 to 3 meters behind the previous stairs, as shown in FIG.

Step 5 Excavation of the upper, middle, and lower central soils f-1, f-2, and f-3 is delayed by 5 to 8 m in order.

Step 6: Lay the geological layer, lay the waterproof layer, and install the secondary lining floor.

Step 7: Install the secondary lining of the arch wall.

Step 2.18 As shown in Figure 7G, after the station body structure is undercut excavated in the entire cross section and entered the tunnel, the waterproof layer of the windway body structure is immediately laid, and then the windway body from bottom to top. Construction of the secondary lining structure will begin in sequence.

Step 2.19 Referring to Figure 7H, after the secondary lining structure of the wind channel body concrete reaches 75% of its design strength, backfill with earth and sand and compact it to restore the ground to its original state.

Includes the main body of the wind duct and a portion exposed from the ground. The parts exposed from the ground are the left piston wind duct, the right piston wind duct, the outside air intake duct, the exhaust duct, the left piston ventilation shaft, the right piston ventilation shaft, the exhaust shaft, the outside air introduction ventilation shaft, and the evacuation entrance. Equipped with. The piston ventilation shaft, ventilation shaft, outside air intake ventilation shaft, and evacuation entrance are constructed using the upside-down pit wall method. After passing through and opening the horsehead gate and entering the tunnel, construction will be carried out using the undercut excavation method.

The main body of the wind channel has a five-layer underground structure and may be constructed using the open cut method. In view of the lack of storage space for ground construction, the present invention recommends a combination of open-cut excavation and undercut excavation for construction. The first underground layer is built using a construction method that combines open-cut excavation and undercut excavation, and four horizontal air ducts, namely a left-right piston air duct, a wind exhaust duct, and an outside air intake air duct, extend from the underground 1st layer, and each has a left-right piston air duct. It leads to the ventilation shaft, ventilation shaft, outside air introduction ventilation shaft, and evacuation entrance. The second to fifth basement levels are the open cut portions of the second stage. The fourth underground level is connected to the station hall level of the station main body, and the fifth underground level is connected to the section tunnel and the platform level of the station main body. Piston wind and heat generated when a train enters and exits the station through the five underground levels of the windway during operation travels from the main body of the windway to four horizontal airways and then propagates to the outside environment through four ventilation shafts.

Since the projecting type wind duct body is located between the section and the station main body, in the overall construction plan, the open cut foundation shaft of the wind duct main body is a slag discharge shaft or a shield starting reception shaft required for the station body and section tunnel. It may also be considered as a pit. Compared to the case of temporarily establishing a shaft or installing a diagonal shaft, a foundation shaft is relatively large in scale and has fewer bends, making it easier to construct, accelerating the construction progress and shortening the construction period. As an auxiliary structure to a station, it does not need to be backfilled afterwards, and has a higher economic effect.

Obviously, the above illustrations and descriptions are merely illustrative and are not intended to limit the disclosure, application, or use of the invention. Having already been described in the Examples and illustrated in the drawings, the present invention may be carried out by way of example of the drawings and in the currently considered best mode of implementation of the teachings of the invention. Rather than being so limited, the scope of the invention includes any embodiments falling within the scope of the foregoing specification and appended claims.

Claims (11)

A protruding type wind duct structure for a deep subway station, the protruding type wind duct structure being composed of a wind duct main part and a wind duct separation part that can be constructed simultaneously in parallel during construction,
The wind duct body part is
Phase 1 open cut foundation shaft,
an undercut excavation dome space horizontally adjacent to the open cut foundation shaft of the first stage;
a second stage open cut foundation shaft adjacent to the entire lower part of the first stage open cut foundation shaft and the undercut excavation dome space;
a third stage open cut foundation shaft adjacent to the entire lower part of the second stage open cut foundation shaft;
A first piston wind passage horizontal passage part on the wind passage main body side, a second piston wind passage horizontal passage part on the air passage main body side, and a wind passage main body side, each extending horizontally from the open cut foundation shaft of the second stage. The side passage of the ventilation duct and the side passage of the outside air introduction wind duct on the side of the wind duct main body.
It is equipped with
The airway separation part is
One end communicates with the ground, the other end communicates with the first piston air passage horizontal passage on the side of the air passage main body, and together with the first piston air passage horizontal passage on the air passage main body side, the first piston air passage a first piston air passage side passage part on the side of the separated part, which constitutes a side passage;
One end communicates with the ground, the other end communicates with the second piston air passage horizontal passage on the side of the air passage main body, and the second piston air passage is connected to the second piston air passage horizontal passage on the side of the air passage main body. a second piston air passage side passage part on the side of the separation part, which constitutes a side passage;
One end communicates with the ground, the other end communicates with a cross-exhaust passage on the side of the airway main body, and together with the cross-exhaust passage on the side of the airway main body constitute a cross-exhaust passage. The side passage of the ventilation duct on the side of the separation part,
One end communicates with the ground, and the other end communicates with the outside air introduction wind passageway on the side of the airway main body, and the outside air introduction windway horizontal passageway is connected to the outside air introduction windway side passageway on the side of the airway main body. The external air introduction wind passage on the separation part side and
It is equipped with
The third stage open-cut foundation shaft of the main part of the wind route is located between the section tunnel through which the subway passes and the station main part of the deep subway station, and is located between the section tunnel through which the subway passes and the station main part of the deep subway station, and is located between the section tunnel and the station main part of the deep subway station. It communicates with
The subway from the section tunnel and the station main part can enter the third stage open cut foundation of the wind road main part, and the third stage open cut foundation of the wind road main part A projecting type wind duct structure for a deep subway station , which is configured so that a subway from a pit can advance into the section tunnel and into the station main body . The maximum horizontal width of the wind duct main body portion is smaller than the maximum width of the wind duct main body portion in the height direction,
The protruding type air duct structure for a deep subway station according to claim 1, wherein the horizontal cross-sectional area of the air duct main body portion is larger than the cross-sectional area of the air duct cross passage. A construction method for a protruding type wind passage for a deep subway station, wherein the protruding type air passage is composed of a wind passage main part and a wind passage separation part that can be constructed simultaneously in parallel during construction,
The construction of the wind duct separation part is as follows:
Step 1: Construct a closed ring beam at the positions exposed from the ground of the left line piston ventilation shaft, right line piston ventilation shaft, exhaust shaft, and outside air introduction ventilation shaft, and install the foundation embedded members to raise the shaft turret. .1 and
step 1.2 of excavating the earth and rock of the shaft and supporting it as it is excavated;
step 1.3 of initially spraying concrete and installing lattice steel frames and reinforcing bar mesh;
step 1.4 of applying shotcrete to seal the surrounding rock;
step 1.5, repeating steps 1.2 to 1.4 until drilling to the bottom elevation of the shaft;
step 1.6 of sealing the bottom of the shaft;
Three lattice steel frames were connected and erected at the positions of the left piston ventilation shaft, right piston ventilation shaft, exhaust shaft, and outside air introduction ventilation shaft, respectively, and mortar anchor bolts were driven. Step 1.7 of setting
Some left piston wind passages are excavated in the entire cross section of the left piston ventilation shaft, right piston ventilation shaft, exhaust shaft, outside air introduction ventilation shaft, some right piston ventilation passages, and one right piston ventilation shaft. step 1.8, installing anchor bolts from the side passages of the ventilation ducts in the section and the lateral passages of the part of the outside air intake ducts, tying up the reinforcing bars, and spraying concrete;
Step 1.9 of laying the bedrock waterproofing layer and constructing the bedrock;
step 1.10 of laying the remaining waterproof layer and performing secondary lining of the arch and side walls;
repeating steps 1.8 to 1.10 until some piston airway cross passages are completed, step 1.11;
The construction of the main body of the wind duct is as follows:
Before excavation, the water level in the pit is lowered , the groundwater level is lowered to a point 1m lower than the excavation surface of the final foundation pit, and surface water is drained by creating a water intake channel on the shoulder of the slope and hardening the ground. Step 2.1 to prevent seepage into the buttocks;
Step 2.2 of driving one stage of steel pipe piles into the rocky strata;
Construct the top beam, erect the flange brace, and drive the prestressed anchor bolts in step 2.3, and excavate the earth and sand downwards to form the first stage open-cut foundation shaft in one layer from top to bottom. Step 2.4: excavating in stages, spraying one layer of concrete after excavation to seal the surrounding rock, then driving anchor bolts, hanging reinforcing bars, and then constructing shotcrete panels;
step 2.5, in which the first stage open-cut foundation shaft is excavated one layer at a time up to the elevation of the dome leg foundation, that is, the elevation of the top of the primary lining of the horizontal lateral passage, and the construction of the undercut excavation dome portion begins;
step 2.6 of pouring a previously placed pipe roof in the open cut foundation pit;
step 2.7 of sealing the face with 100-200 mm thick shotcrete or 200-500 mm thick concrete;
Step 2: First, tunnels on both sides are excavated in sequence, concrete is sprayed to seal the surrounding rocks, lattice formwork is erected, temporary steel shoring is erected, reinforcing bars are tied together, and concrete is sprayed. .8 and
Step 2: After each lattice formwork is erected, dig out the soft soil of the lattice legs and install a 100mm thick shotcrete underlayment as a foundation for the lattice legs to ensure the lattice is stable. .9 and
Two central guide shafts were excavated about 5 meters apart in the vertical direction, and after the excavation, concrete was immediately sprayed to seal the surrounding rocks, lattice formwork was erected, temporary steel shoring was erected, and a reinforcing bar net was installed. Step 2.10 of tying and spraying concrete;
step 2.11 of constructing the dome structure and removing the central temporary shoring in stages;
step 2.12 of excavating a second stage open-cut foundation shaft while being protected by a dome structure;
step 2.13 of excavating to the bottom elevation of the windway cross passage, then temporarily stopping the excavation, opening horsehead gates on both sides and starting to enter the tunnel, and excavating the four remaining windway cross passages;
After completing the secondary lining construction for the remaining windway side passages, we will continue to excavate the lower part of the earth and sand, and open the third stage from the bottom elevation of the windway sideways along the outer contour of the station main structure. step 2.14 in which the excavated portion of the cut foundation shaft is partitioned vertically;
Step 2.15 of continuing to excavate downward into the steel pipe pile and immediately shoring;
When a pit is excavated more than 300mm from the base of the foundation, the foundation is inspected, the remaining soil is manually dug out, and after the excavation reaches the design elevation, the foundation is leveled immediately to drain the water that has accumulated inside the pit. step 2.16 of immediately applying an underlay;
step 2.17 of carrying out undercut excavation construction of the station main part of the deep subway station from the third stage open cut foundation shaft of the wind channel main part ;
After entering the tunnel by undercutting the entire section of the station main structure, a waterproof layer for the windway main structure is laid, and then the secondary lining structure for the windway main body is installed sequentially from the bottom to the top. step 2.18,
After the secondary lining structure of the wind channel main body concrete reaches 75% of the design strength, step 2.19 of backfilling and compacting earth and sand to return the ground to its original state;
The third stage open cut foundation shaft of the windway main body part is located between the section tunnel through which the subway passes and the station main part, and communicates with the section tunnel and the station main part,
The subway from the section tunnel and the station main part can enter the third stage open cut foundation of the wind road main part, and the third stage open cut foundation of the wind road main part The subway from the pit is configured to be able to advance into the section tunnel and into the station main body part,
A method of constructing a protruding wind passageway for a deep subway station, which is characterized by the following. In step 2.6, in order to ensure the construction accuracy of the long pipe roof, the guide steel pipe with a diameter of 140 mm and a wall thickness of 5 mm is set to L = 0.8 m, and the long pipe roof covers the entire horizontal depth of the dome. The construction method of a protruding type wind passage for a deep subway station according to claim 3 . The long pipe roof is 16 m long, and each section is made up of 4 m long hot-rolled seamless steel pipes connected with screws.Cement slurry is used for injection, with a water-cement ratio of 1:1 and injection pressure. 0.5 to 2.0 MPa , and after the injection is completed, the steel pipe is filled with M7.5 cement mortar to strengthen the strength of the pipe roof. How to construct a wind path. The second stage open cut foundation shaft in step 2.12 is divided into two parts, one part continues to excavate downward from the first stage foundation shaft, and the other part continues to excavate from the undercut excavation part to the dome. Top-down excavation is carried out downward while being protected by the ground.During construction, the principle of first-branch-back excavation is used, and after excavation, one layer of concrete is immediately sprayed to seal the surrounding rock, and then anchor bolts are driven. 4. The method of constructing a protruding windway for a deep subway station according to claim 3 , wherein the shotcrete panels are constructed after the reinforcing steel mesh is installed. In step 2.13, the tunnel entrances of the remaining left piston wind passages and the remaining outside air introduction wind passages are located below the first stage open cut foundation shaft, and the remaining right piston wind passages are located below the first stage open cut foundation shaft. 4. The method of constructing a protruding type wind duct for a deep subway station according to claim 3 , wherein the tunnel entrances of the road side passage and the remaining ventilation passages are located below the dome. Entry into the tunnel of the remaining left piston wind passage below the open cut foundation shaft and the remaining outside air introduction wind passage is performed by full-section excavation, specifically,
Step A: excavating the entire cross section, installing anchor bolts, tying up the reinforcing steel mesh, and spraying concrete;
Step B of laying the bedrock waterproofing layer and constructing the bedrock;
Step C, in which the remaining waterproof layer is laid and secondary lining is applied to the arch part and side walls, and the secondary lining progress of the arch part and side walls is one excavation progress slower than that of the inverted rock arch; 8. The method of constructing a protruding type wind passage for a deep subway station according to claim 7 . The remaining right-hand piston wind passageway and the remaining ventilation passageway below the dome are excavated by the middle wall construction method, and specifically,
The left-hand shaft was excavated, concrete was immediately sprayed initially to seal the surrounding rocks, lattice steel formwork and vertical temporary I-shaped steel supports were erected, and the reinforcing bar network was tied together, then concrete was poured to a thickness of 150 mm. Step A of spraying
A right-hand shaft was excavated with a shift of 0.5 m, concrete was immediately sprayed initially to seal the surrounding rock, lattice steel forms were erected, and each lattice was erected to ensure that the lattice was stable. Afterwards, Step B involves digging out the soft soil at the base of the lattice legs and applying a 100mm thick shotcrete underlay as the foundation for the lattice legs;
After the dome reaches its design strength, step C of removing the temporary steel beam support and constructing a secondary lining structure for the wind channel at the horse gate;
According to claim 7 , the step D includes a step D in which the length of the horse head part is about 3 m, the excavation depth is set to 0.5 m or less, and the excavation is performed using the full cross-section method after leaving the horse head part. Construction method for protruding wind passages at deep subway stations. A claim characterized in that the four remaining wind passageways and some of the horizontal passageways excavated from the ventilation shaft in step 1.11 are joined together to form a completely communicating wind passageway. The method for constructing a protruding wind duct for a deep subway station as described in item 7 . In step 2.17, the station body to be undercut excavated from the foundation shaft of the wind passage main body is excavated by a three-step construction method and a seven-step method. construction method.